add selection manager

src/Umbraco.Web.UI.Client/libs/utils/index.ts

@@ -1,2 +1,3 @@
 export * from './umbraco-path';
 export * from './udi-service';
+export * from './selection-manager';

src/Umbraco.Web.UI.Client/libs/utils/selection-manager.ts

@@ -0,0 +1,61 @@
+import { Observable } from 'rxjs';
+import { UmbArrayState, UmbBooleanState } from '../observable-api';
+
+export interface UmbSelectionManager {
+	selection: Observable<Array<string | null>>;
+	multiple: Observable<boolean>;
+
+	getSelection(): Array<string | null>;
+	setSelection(value: Array<string | null>): void;
+
+	getMultiple(): boolean;
+	setMultiple(value: boolean): void;
+
+	toggleSelect(unique: string | null): void;
+	select(unique: string | null): void;
+	deselect(unique: string | null): void;
+	isSelected(unique: string | null): boolean;
+}
+
+export class UmbSelectionManagerBase implements UmbSelectionManager {
+	#selection = new UmbArrayState(<Array<string | null>>[]);
+	public readonly selection = this.#selection.asObservable();
+
+	#multiple = new UmbBooleanState(false);
+	public readonly multiple = this.#multiple.asObservable();
+
+	public getSelection() {
+		return this.#selection.getValue();
+	}
+
+	public setSelection(value: Array<string | null>) {
+		if (value === undefined) throw new Error('Value cannot be undefined');
+		this.#selection.next(value);
+	}
+
+	public getMultiple() {
+		return this.#multiple.getValue();
+	}
+
+	public setMultiple(value: boolean) {
+		this.#multiple.next(value);
+	}
+
+	public toggleSelect(unique: string | null) {
+		this.isSelected(unique) ? this.deselect(unique) : this.select(unique);
+	}
+
+	public select(unique: string | null) {
+		const newSelection = this.getMultiple() ? [...this.getSelection(), unique] : [unique];
+		this.#selection.next(newSelection);
+	}
+
+	public deselect(unique: string | null) {
+		const newSelection = this.getSelection().filter((x) => x !== unique);
+		this.#selection.next(newSelection);
+	}
+
+	public isSelected(unique: string | null) {
+		return this.getSelection().includes(unique);
+	}
+}